This module, when combined with connection tracking, allows access to
the connection tracking state for this packet.
.TP
.BI "--state " "state"
Where state is a comma separated list of the connection states to
match.  Possible states are
.B INVALID
meaning that the packet could not be identified for some reason which
includes running out of memory and ICMP errors which don't correspond to any
known connection,
.B ESTABLISHED
meaning that the packet is associated with a connection which has seen
packets in both directions,
.B NEW
meaning that the packet has started a new connection, or otherwise
associated with a connection which has not seen packets in both
directions, and
.B RELATED
meaning that the packet is starting a new connection, but is
associated with an existing connection, such as an FTP data transfer,
or an ICMP error.